Project record

Dakar Mamelles desalination intake and brine discharge

Split view of an offshore intake structure being lowered beside the Mamelles coast and the intake pipe inside its concrete microtunnel

Eiffage Génie Civil Marine, Mamelles project update

Dakar's first large seawater desalination plant is in its commissioning year after Eiffage recorded a 340 m seawater-intake microtunnel milestone in July 2025. The 50,000 m3/day plant was still under construction during a supervision visit in February 2026. The older JICA design basis also carried a separate 500 m brine-discharge line; current public updates leave its final geometry, installation and marine acceptance unconfirmed.

Project signal

Construction in Senegal

Separate the current construction record from the 2015 design baseline. Eiffage confirms the 340 m intake drive, and TPF confirms that the plant remained under construction in February 2026. JICA's preparation study defined twin 350 m intake lines and a 500 m discharge line; those dimensions are design history, not an as-built statement. Commissioning, first water and programme completion still require owner or lender evidence.

Current status Plant remained under construction in February 2026; commissioning was expected later in 2026, while final marine handover evidence remains unpublished Source confidence Confirmed

Location

Senegal / Africa

Segment

Marine utilities

Status

Plant remained under construction in February 2026; commissioning was expected later in 2026, while final marine handover evidence remains unpublished / Confirmed

Evidence reviewed

19 July 2026

Controlled taxonomy

Related sectors

The detailed segment above is the primary work classification. These broader sector links connect the project to related delivery and market research.

Project anatomy

Scope, counterparties, and execution logic

Client / authority
Société Nationale des Eaux du Sénégal (SONES)
Delivery parties
Toyota Tsusho-led consortium with Eiffage Génie Civil and VA Tech Wabag, TPF consultancy and supervision
Contract route
JICA ODA loan SE-P3; international competitive CP-1 design-build and operating package awarded to the Toyota Tsusho-led consortium, with two years of operation and maintenance after construction
Execution window
Toyota Tsusho's 2022 order carried a 2025 planned completion. TPF's 10 February 2026 visit still described the plant as under construction and expected commissioning later in 2026. JICA's May 2026 Senegal programme lists the wider Mamelles programme through 2029.
Works package
Initial 50,000 m3/day seawater reverse-osmosis plant expandable to 100,000 m3/day; seawater intake and pumping, intake transmission, brine discharge, treatment, product-water pumping and transmission, power connection, distribution-main installation and wider Dakar network renewal
Marine interfaces
Eiffage recorded a 340 m seawater-intake microtunnel drive in July 2025. The 2015 JICA preparation basis carried two 1,200 mm intake lines of about 350 m each and a 710 mm brine-discharge line of about 500 m, but later public construction updates reviewed by IMWO do not reconcile the final discharge geometry or publish marine acceptance.
Commercial read
The main plant contract is in construction, not a new tender. The open specialist questions now sit at the interface between completed intake tunnelling, discharge installation, process commissioning and owner acceptance. The original 2025 completion date has passed, while the wider JICA programme continues beyond the plant's stated 2026 commissioning target.
Next milestone
Owner or lender confirmation of final brine-discharge installation, intake and discharge testing, process wet commissioning, first compliant water, marine environmental results and formal operating release

Material change register

What changed, when, and what it proves

Only source-bound events that alter phase, scope, counterparties, delivery, completion, commissioning, or acceptance are listed. A change can advance the record without proving the next gate.

The plant remained under construction in its commissioning year

TPF's supervision visit confirmed active construction and an expectation of commissioning later in 2026, superseding the original 2025 completion plan without proving operating release.

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Eiffage recorded the 340 m intake microtunnel milestone

The intake route moved from design into physical evidence. The update did not publish final brine-discharge installation or marine acceptance.

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The main plant and operating order was announced

Toyota Tsusho identified the SONES client, consortium, initial 50,000 m3/day capacity and two-year O&M obligation, with an original 2025 completion plan.

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Delivery watch

Evidence needed next

Owner or lender confirmation of final brine-discharge installation, intake and discharge testing, process wet commissioning, first compliant water, marine environmental results and formal operating release

Decision watchpoints

  • Final intake geometry and hydraulic testing
  • Brine-discharge line, head and diffuser installation
  • Marine survey and environmental acceptance
  • Process wet commissioning and first water
  • 50,000 m3/day performance test
  • Power and product-water network readiness
  • Owner operating release and two-year O&M start
  • Phase 2 expansion boundary to 100,000 m3/day

Related records 2

Project availability status

This public project page is a tracked market record rather than a tender notice, contractual commitment, or commercial instruction. Use the status, confidence label, evidence-review date, and source note together when judging how much weight to place on the signal.

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Record control

Evidence reviewed date is not a project-event date.

IMWO changes phase, participants, scope, completion, or acceptance wording only when a dated source establishes the change. The review date records when the evidence set was checked; it does not claim that physical work changed on that date.

Evidence reviewed 19 July 2026 Sources in this record 6

Source record

JICA's May 2026 Senegal programme is the current lender-side schedule reference and lists Mamelles as a 2016-2029 loan project. TPF's 10 February 2026 site visit confirms the plant remained under construction and records an expectation of commissioning later in 2026. Eiffage's 1 July 2025 update confirms the 340 m intake microtunnel milestone. Toyota Tsusho identifies the client, consortium, 50,000 m3/day capacity, two-year O&M period and original 2025 completion plan. SONES supplies the owner-side system and financing context. JICA's 2015 study supplies design-stage marine dimensions only; it is not used as current as-built evidence.

Phase: construction. Evidence reviewed: 19 July 2026.

Project sources 6